Coolant Replacement

GENERAL INFORMATION

Coolant must be replaced only after repair of the cooling system when the coolant has been drained. Coolant replacement during maintenance is not provided for. If the cylinder head, cylinder head gasket, radiator, heat exchanger or engine was replaced during repair, the coolant must always be replaced. This is necessary because during the break-in period, protective additives are deposited on light alloy engine components and form a corrosion protection layer. If used coolant is installed, its composition does not allow the required protective layer to form on new engine components.

CAUTION

Coolant is slightly toxic and must not be poured in places not intended for its disposal. Local authorities must provide information on coolant disposal sites.

REMOVAL

CAUTION

There is a risk involved when lifting and supporting the vehicle on stands! Therefore, first read the subsection Jacking Up the Vehicle.

PROCEDURE

1. Raise the vehicle and support it on stands.

2. Remove the engine undercover. Refer to Engine Undercover Removal and Installation.

CAUTION

Before removing the expansion tank cap on a hot engine, place a thick rag over it to prevent scalding from hot coolant and steam. Remove the tank cap only when coolant temperature is below +90°C.

3. Open the expansion tank cap.

4. Place a clean container under the radiator.

5. Open the drain plug (arrow in illustration) by turning it counterclockwise. It is recommended to attach a hose to the drain connection. Collect the draining coolant.

6. Diesel and some gasoline engines: Additionally disconnect the coolant hose from the bottom of the oil/coolant radiator (oil cooler). To do this, open the clamp using HAZET 798-5 and slide it fully back. The oil cooler is located at the oil filter flange. Drain the oil completely.

FILLING

7. Prepare a mixture of 50 % water and 50 % antifreeze/corrosion protection agent. Refer to Antifreeze – Anti-Freeze Agent subsection.

8. Install the coolant hose onto the oil cooler and secure it with the clamp.

9. Tighten the drain plug on the radiator.

10. Install the engine undercover. Refer to Engine Undercover Removal and Installation.

11. Lower the vehicle to the wheels.

12. Slowly fill the system up to the MAX mark on the expansion tank.

13. Start the engine and run it at increased speed of approx. 1500 rpm for about 2 min. While doing so, fill the expansion tank with coolant up to the overflow opening.

14. Close the expansion tank.

15. Start the engine so that the electric cooling fan switches on.

16. Switch off the engine and allow it to cool down.

17. Check the coolant level and top up if necessary. With a warm engine, the coolant level must reach the MAX mark; with a cold engine, it must be between the MAX and MIN marks.